Journal of Veterinary Internal Medicine最新文献

Background: Cerebral microbleeds (CMBs) are a possible sequela in human brain tumor patients treated with radiation therapy (RT). No such association is reported in dogs.

Objectives: To investigate whether CMBs occur in dogs after radiotherapy, and if there is an association between number and dose, and an increase over time.

Animals: Thirty-four client-owned dogs irradiated for primary intracranial neoplasia. ≥2 magnetic resonance imaging (MRI) scans including susceptibility-weighted imaging (SWI) were required.

Methods: Retrospective, observational, single-center study. Cerebral microbleeds identified on 3 T SWI were counted within the entire brain, and within low- (<20 Gy), intermediate- (20-30 Gy), and high- (>30 Gy) dose regions. A generalized linear mixed-effects model was used to analyze the relationship between the CMBs count and the predictor variables (irradiation dose, time after treatment).

Results: Median follow-up time was 12.6 months (range, 1.8-37.6 months). Eighty-three MR scans were performed. In 4/15 dogs (27%, 95% CI, 10%-52%) CMBs were present at baseline. ≥1 CMBs after RT were identified in 21/34 dogs (62%, 95% CI, 45%-77%). With each month, the number of CMBs increased by 14% (95% CI, 11%-16%; P < .001). The odds of developing CMBs in the high-dose region are 4.7 times (95% CI, 3.9-5.6; P < .001) greater compared with the low-dose region.

Conclusion and clinical importance: RT is 1 possible cause of CMBs formation in dogs. Cerebral microbleeds are most likely to occur in the peritumoral high-dose volume, to be chronic, and to increase in number over time. Their clinical relevance remains unknown.

Background: Functionality of human adrenal tumors is inferred by CYP11B1 (cortisol synthase) expression, CYP11B2 (aldosterone synthase) expression, or both.

Hypothesis/objectives: Nonfunctional canine adrenal tumors have low expression of steroidogenic enzymes, whereas aldosterone-producing tumors express CYP11B, and cortisol-producing tumors express both CYP11B and CYP17.

Animals: Twenty-two client-owned dogs with adrenocortical tumors (ACT) (8 nonfunctional, 7-cortisol producing, 2 aldosterone-producing and 5 functional noncortisol producing) and 2 dogs with normal adrenal glands.

Methods: Retrospective case series. Adrenal functionality was determined from clinical signs and endocrine testing. CYP11A1, CYP11B, CYP17, and HSD3B2 expression was detected by immunohistochemistry on formalin-fixed paraffin-embedded adrenal tissue. Protein expression was semiquantified by 2 blinded observers using H-scoring (results reported as median [range]) and compared in nonfunctional and cortisol-producing adrenal tumors by Mann-Whitney U tests.

Results: CYP11A1, CYP11B, and HSD3B2 were present within all cortical layers of normal adrenal glands, and CYP17 was expressed within the zona fasciculata and zona reticularis. Expression of CYP11A1 (191.25 [97.5-270] vs. 175 [102.5-295] P = .69), CYP11B (190 [130-265] vs. 147.5 [95-202.5]; P = .07), CYP17 (177.5 [87.5-240] vs. 247.5 [55-292.5]; P = .40), and HSD3B2 (230 [47.5-295] vs. 277.5 [67.5-295]; P = .34) were not significantly different between cortisol-producing and nonfunctional ACT.

Conclusions and clinical importance: Our findings suggest it is not possible to determine functionality of canine ACT by immunohistochemistry for steroidogenic enzymes. Tumor size cannot be used to infer functionality of adrenal tumors.

Background: Noninvasive ventilation (NIV) provides effective respiratory support in foals, but face masks are poorly tolerated and associated with hypercapnia. Bi-nasal prongs might be a more effective device interface in foals.

Objectives: To compare bi-nasal prongs and masks for NIV in foals with pharmacologically induced respiratory insufficiency.

Animals: Six healthy foals.

Methods: In a randomized cross-over study, sedated foals received NIV delivered by mask or bi-nasal prongs, with the treatment repeated using the alternative device interface after a 3-day rest period. After periods of spontaneous ventilation through the allocated interface, with and without supplementary O₂ (T2-T3), foals were subject to 10-minute treatment periods of NIV at different pressure support (5 or 10 cmH₂O) and end-expiratory pressure settings (5 or 10 cmH₂O), with and without supplementary O₂ (T4-T7). Vital signs, arterial blood gases, spirometry, and gas exchange data were measured in the final 2 minutes of each treatment window.

Results: Bi-nasal prongs were well tolerated and required less manual positioning or monitoring compared to the mask. Partial pressure of carbon dioxide did not increase during NIV with bi-nasal prongs and was lower than observed with masks (mean difference, 8.2 mmHg [95% confidence interval, 4.1-12.2 mmHg] at T6). Oxygenation and respiratory mechanics were improved in all foals and not different between device interfaces.

Conclusions and clinical importance: Nasal prongs were well tolerated, had similar effects on respiratory function, and appeared to ameliorate hypercapnia observed previously during NIV in foals.

Background: Minimally invasive approaches are the standard for treatment of upper urinary tract uroliths in humans.

Objective: To describe the medical dissolution of upper urinary tract uroliths in a series of dogs and report clinical outcomes.

Animals: 6 female dogs (9 kidneys).

Methods: Retrospective case series. A review of medical records in dogs that underwent medical dissolution of upper urinary tract uroliths utilizing diet, administration of antibiotics, and double-pigtail ureteral stent(s) placement, when indicated, was performed. Medical management was generally continued for 4 weeks beyond urolith dissolution. Information on biochemical, microbiological, imaging, and clinical outcomes before and after dissolution were recorded.

Results: Six dogs (9 kidneys) were included with bilateral (3) or unilateral (3) nephrolithiasis, ureterolithiasis, or a combination. A ureteral stent(s) was placed endoscopically in 5/6 dogs (6/9 kidneys) for obstructive ureterolithiasis (n = 5) or a nonobstructive massive nephrolith (n = 1). All dogs had a positive urine culture of Staphylococcus pseudintermedius with a median urine pH of 7.25 (range, 6.5-8) and 4/5 had pyonephrosis. All dogs had initial evidence of urolith dissolution at a median of 1.1 months (range, 0.42-5.9), with complete dissolution of ureteroliths at a median of 3.9 months (range, 1.5-7.6), nephroliths at 5.3 months (range, 1.5-7.6), and lower urinary tract uroliths at 0.87 months (range, 0.42-5.9). Stents were removed in 3/6 once dissolution was documented. The median follow-up time was 519 days (range, 177-2492 days).

Conclusion and clinical importance: Medical dissolution and decompression of upper urinary tract struvite uroliths should be considered a minimally invasive treatment for dogs before more invasive options.

Background: Limited current information exists regarding discospondylitis within breeds commonly affected by congenital vertebral body malformations.

Hypothesis/objectives: Report the prevalence of discospondylitis in English and French bulldogs and investigate for possible associations of discospondylitis with congenital vertebral body malformations.

Animals: 108 client-owned dogs.

Methods: Retrospective multi-institutional study between June 2010 and 2020. Cases with a diagnosis of discospondylitis on computed tomography (CT) or magnetic resonance imaging (MRI) and complete medical records included. Signalment, discospondylitis location, presence of congenital vertebral body malformations, and the site of maximal kyphosis were recorded.

Results: The prevalence of discospondylitis was 3.4 (1.6-6.7, 95% confidence interval [CI]) times higher in French bulldogs (P < .001) and 4.3 (1.7-9.8, 95% CI) times higher in English bulldogs (<.001), compared with the overall hospital cohort. One or more vertebral malformations were present in 12 French bulldogs (92.3%), 6 English bulldogs (75.0%), and 1 "other" breed dog (1.1%). Discospondylitis was diagnosed adjacent to congenital vertebral body malformations in 12 (80%) intervertebral discs in French bulldogs and 5 (50%) intervertebral discs in English bulldogs. The median age at presentation was significantly younger in French bulldogs (1.1 years; range, 0.5-9.2 years) and English bulldogs (1.0 years; range, 0.4-7.0 years), compared with "other" breed dogs (7.3 years; range, 0.3-14.0 years; both P < .001).

Conclusions and clinical importance: Congenital vertebral body malformations were frequently associated with discospondylitis in French and English bulldogs, with clinical signs commonly encountered at a significantly younger age.

Background: New feline erythrocyte antigens (FEAs) have been described based on the presence of naturally occurring alloantibodies (NOAb), but their immunogenicity and clinical relevance are poorly understood.

Hypothesis/objectives: Describe the immunogenicity of FEA 4 after sensitizing FEA 4-negative cats lacking NOAb and characterize anti-FEA 4 alloantibodies produced, including their rate of appearance, agglutination titer, and immunoglobulin class.

Animals: Nineteen healthy type A cats were blood typed for FEAs 1 to 5 to identify suitable donor-recipient pairs for FEA 4 sensitization.

Methods: Four FEA 4-negative cats were transfused with FEA 4-positive red blood cells. Using a gel column technique, posttransfusion samples were screened daily for a week, weekly for a month, and monthly thereafter for anti-FEA 4 alloantibodies.

Results: Alloantibodies were not detected in the first 3 recipients despite repeated transfusions (1 and 3 additional transfusions for 2 and 1 recipients, respectively). In the 4th recipient, alloantibodies against its donor red blood cells were detected 21 days postsensitization. However, they were not directed against FEA 4, but rather against a novel FEA not yet described. The alloantibodies, named anti-FEA 6, remained detectable for >4 months after sensitization and were determined to be mostly immunoglobulin M based on sulfhydryl treatment.

Conclusions and clinical importance: Feline erythrocyte antigen 4 does not appear to be immunogenic because repeated sensitization of 4 cats failed to produce detectable anti-FEA 4 alloantibodies. A new immunogenic antigen, named FEA 6, has been discovered, but additional studies are needed to document its clinical importance.

Background: Reference intervals for simple body weight-independent measurements of right heart size and function are limited.

Objectives: Generate reference intervals for measurements of right heart size indexed to the long-axis aortic valve diameter (AoD) or corresponding left heart structure (right heart ratios) and describe the reproducibility of these indices.

Animals: Ninety healthy adult dogs of variable body weight.

Methods: Prospective study. All dogs underwent an echocardiogram performed by the same operator. Numerous linear 2-dimensional measurements of right heart size and function from different imaging planes were performed. Eight dogs underwent repeated echocardiograms by the same operator on 3 different days, and 3 different operators performed repeated echocardiograms on the same day. Reference intervals were generated using the Clinical Laboratory Standards Institute method. Reproducibility was quantitated using coefficients of variation (CVs) and reproducibility coefficients.

Results: Reference intervals for right heart ratios were generated and allow simple assessments of right heart size and function that do not require a scaling exponent or body weight table. Right heart ratios did not show clinically relevant associations with body weight. All CVs were <22.6%. In general, CVs for right heart measurements indexed to AoD were lower compared with right heart measurements indexed to the corresponding left heart structure.

Conclusions and clinical importance: Reference intervals for simple body weight-independent right heart ratios are available to help detect abnormalities of right heart size and function. Reproducibility coefficients might be useful to help identify meaningful changes in right heart size during serial evaluations.

Background: It is unknown if gastrointestinal dysbiosis in diarrheic calves causes disease or is a consequence of the disease.

Objectives: Describe the fecal microbiota of calves before, during, and after recovering from diarrhea.

Animals: Fifteen female Holstein calves of 0 to 21 days old from a single farm. Seven calves remained healthy throughout the study, and 8 developed diarrhea on Day 14.

Methods: Longitudinal cohort study. Microbiota composition was characterized by amplifying the V4 region of the 16S rRNA gene.

Results: Diversity (Shannon index) increased with age in healthy and diarrheic calves from Day 3 to 21, but diarrheic calves had a lower diversity on the day diarrhea was first observed (Day 14). By Day 21, diversity increased in calves that recovered from diarrhea and was not significantly different from that of their healthy counterparts (P > .05). Weighted UniFrac distance showed significant differences in the fecal microbiota between diarrheic and healthy calves at Day 14 of age (PERMANOVA, P < .05), but not before or after diarrhea (PERMANOVA, P > .05). Lactobacillus, Clostridium Sensu Stricto 1, and Collinsella were differentially abundant on Day 10 in calves that developed diarrhea on Day 14 (P < .05).

Conclusion and clinical importance: The fecal microbiota of healthy and diarrheic calves evolved similarly during the first 10 days of age but differed significantly on the day of onset of diarrhea. Enriching Lactobacillus, Clostridium Sensu Stricto 1, and Collinsella before diarrhea onset could have been contributed to the development of diarrhea.

Background: Reliability of echocardiographic calculations for stroke volume and mitral regurgitant fraction (RF_MR) are affected by observer variability and lack of a gold standard. Variability is used to calculate critical change values (CCVs) that are thresholds representing real change in a measure not associated with observer variability.

Hypothesis: Observed intra- and interobserver accuracy and variability in healthy dogs help model CCV for RF_MR.

Animals: Reliability cohort of 34 healthy dogs; allometric scaling cohort of 99 dogs with heart disease and 25 healthy dogs.

Methods: Accuracy, variability, and CCV of 2 observers using geometric and flow-based echocardiography were prospectively compared against a standard of RF_MR = 0% and extrapolated across a range of expected RF_MR values in the reliability cohort partly derived from cardiac dimensions predicted by the allometric cohort.

Results: Accuracy of methods to determine RF_MR in descending order was 4-chamber bullet (Bullet_4CH), mitral inflow, cube formula, and Simpson's method of disks. Intraobserver variability was relatively high. The CCV for RF_MR ranged from 28% to 88% and was inversely related to RF_MR when extrapolated for use in affected dogs. For both observers, the Bullet_4CH method had the lowest intraobserver CCV (Operator 1:28%, Operator 2:41%). Interobserver strength of agreement was low with intraclass correlation coefficients ranging from 0.210 to 0.413.

Conclusions and clinical importance: Echocardiographic volumetric methods used to calculate stroke volume and RF_MR have low accuracy and high variability in healthy dogs. Extrapolation of observed CCV to a range of expected RF_MR suggests observers and methods are not interchangeable and variability might hinder routine clinical usage. Individual observers should be aware of their own variability and CCV.